1. Field of the Invention
The present invention relates to a method of manufacturing the thin-film magnetic head which performs a magnetic recording action by a perpendicular magnetic recording scheme, the thin-film magnetic head, a head gimbal assembly, and a hard disk drive.
2. Related Background Art
A hard disk drive has a large recording capacity and is used as the heart of a storage device. The hard disk drive records and reproduces data to/from a hard disk (recording medium) by a thin-film magnetic head.
The thin-film magnetic heads can roughly be classified according to their recording schemes into those of longitudinal magnetic recording type and those of perpendicular magnetic recording type. The longitudinal magnetic recording scheme records data in a (longitudinal) direction within a recording surface of a hard disk (recording medium), while the perpendicular magnetic recording scheme records data such that the direction of recording magnetization formed in the hard disk is made perpendicular to the recording surface. The thin-film magnetic heads of perpendicular magnetic recording type have been considered more promising than those of longitudinal magnetic recording type, since they can realize a much higher recording density than that in the longitudinal magnetic recording scheme, while their recorded hard disks are less susceptible to heat fluctuation.
Meanwhile, a conventional magnetic head of perpendicular magnetic recording type (perpendicular magnetic recording head which will also be referred to as “PMR” in the following) has a magnetic pole layer and a thin-film coil. The PMR has a structure of electromagnet which the thin-film coil are wound around the magnetic pole layer.
For example, a conventional PMR has a main magnetic pole layer having a magnetic pole end face on a side of a medium-opposing surface opposing a recording medium, a thin-film coil which generates a magnetic field passes through the inside of the main magnetic pole layer, and a return magnetic pole layer linked to the main magnetic pole layer through a linking part.
Meanwhile, a PMR that a shield layer is formed near the main magnetic pole layer is known. For example, in JP 2010-157303 (referred to also as Patent Document 1), the PMR that the shield layer is formed on a leading side of the main magnetic pole layer is disclosed. In this PMR, an end face of the shield layer is disposed in the medium-opposing surface together with a magnetic pole end part of the main magnetic pole layer. Besides, in JP 2008-97826 (referred to also as Patent Document 2), the PMR that the shield layer is formed on a trailing side of the main magnetic pole layer is disclosed. In this PMR, the end face of the shield layer is disposed in the medium-opposing surface together with a magnetic pole end part of the main magnetic pole layer, too.